Operating Power Levels Research Articles

Transient recovery from heat pipe dryout by power throttling

Heat pipes and vapor chambers are passive heat spreaders driven by capillary pumping of an internal working fluid via a porous wick. The capillary limit is the maximum steady-state heat input at which the fluid pressure drop can be supported by the capillary pressure head generated in the wick. However, heat pipes and vapor chambers often find application in devices where the heat input is highly transient and can exceed the capillary limit for brief time intervals. Operating heat pipes briefly above the capillary limit will not result in a dryout if the operating time interval does not exceed a characteristic time-to-dryout. Operation over a duration that exceeds this time-to-dryout can induce transient dryout and may lead to thermal hysteresis, that is, the original heat pipe thermal resistance may not be recovered even after the heat input is lowered back below the capillary limit. To fully recover the heat pipe performance after a transient dryout event, our recent experiments have shown that the heat input must be lowered (or throttled) significantly below the capillary limit. Due to the highly transient nature of power dissipation from electronic devices, it becomes imperative to characterize the throttling power level and duration required to ensure full recovery of a heat pipe from dryout under transient operations. This work experimentally characterizes recovery of heat pipes from dryout by power throttling under transient conditions, where ‘power throttling’ is the act of reducing the operating power level significantly below the capillary limit to eliminate post-dryout thermal hysteresis. We deduce from the experiments that the power must be throttled for longer than a minimum throttling time interval, defined as the time-to-rewet, in order to eliminate dryout-induced thermal hysteresis. The dependence of this time-to-rewet on the throttling power level is explored, and guidelines are presented on the need for throttling and the choice of throttling power under transient conditions.

Design and analysis for the SPICE parameters of waveform-selective metasurfaces varying with the incident pulse width at a constant oscillation frequency

In this study, we numerically demonstrate how the response of recently reported circuit-based metasurfaces is characterized by their circuit parameters. These metasurfaces, which include a set of four diodes as a full wave rectifier, are capable of sensing different waves even at the same frequency in response to the incident waveform, or more specifically the pulse width. This study reveals the relationship between the electromagnetic response of such waveform-selective metasurfaces and the SPICE parameters of the diodes used. In particular, we draw conclusions about how the SPICE parameters are related to (1) the high-frequency operation, (2) input power requirement and (3) dynamic range of waveform-selective metasurfaces with supporting simulation results. First, we show that reducing a parasitic capacitive component of the diodes is important for realization of the waveform-selective metasurfaces in a higher frequency regime. Second, we report that the operating power level is closely related to the saturation current and the breakdown voltage of the diodes. Moreover, the operating power range is found to be broadened by introducing an additional resistor into the inside of the diode bridge. Our study is expected to provide design guidelines for circuit-based waveform-selective metasurfaces to select/fabricate optimal diodes and enhance the waveform-selective performance at the target frequency and power level. Our results are usefully exploited to ensure the selectivity based on the pulse duration of the incident wave in a range of potential applications including electromagnetic interference, wireless power transfer, antenna design, wireless communications, and sensing.

Analysis of variable reverse osmosis operation powered by solar energy

The use of solar photovoltaic (PV) to power reverse osmosis (RO) plants and produce water will enhance the sustainability of water supplies in several dry remote coastal areas. Varying the operating power level of the RO plant has been proposed in the literature as a solution to accommodate intermittent PV power sources. Such variable operation is intended to match the RO load to the available PV power. Nevertheless, such operation has not been used outside research laboratories and small pilot plants. In this work, we used different case studies to evaluate the benefit of using variable operation and its effects on system design, system operation and levelized cost of water (LCOW). A simulation model for the optimal operation of the system is developed using three-dimensional dynamic programming (DP) to determine the power levels of the battery, diesel generator, and RO plant while optimal sizing of these plants and associated water tanks and PV generators was solved using an ordinal optimization (OO) approach. The use of OO permitted the examination of a large design search space quickly but exhaustively using a simple model. We then ranked the different designs in increasing cost order and assessed a reduced number of these using an accurate model to simulate the system on an hourly basis for all the days of a year. This approach relies on the fundamental tenet of OO: “order is robust to the noise introduced by the simple model”. Different power modulation strategies are investigated, and their implications on the hydraulic operating parameters are presented. In this respect, we investigate the operation of the RO system at varying power levels and different sizes of backup systems (battery and diesel generator). This ability to vary the RO operating level helped in a better matching of the system load to the available, yet variable, PV power, even when the backup and storage systems were at a minimum. Operating an RO plant with PV and backup systems is found to be far more cost effective than operation without backup systems, reducing costs by 37–55% for the case studies considered.

Design and analysis of the output windows of a doorknob structure for high-power P-band klystron

This article presents the design, analysis, and simulation for the klystron coaxial radio frequency (RF) output windows. Three new RF windows (Type-2, 3, and 4) are proposed based on the coaxial RF window with a doorknob structure (Type-1) to improve its performances. The proposed RF windows are simulated in high frequency simulator structure. At the operating frequency, the return loss are obtained as −49, −60, −56, and −52 dB, and the insert loss as −0.003 62, −0.002 51, −0.002 74, and −0.003 dB, respectively, for Type1, 2, 3, and 4. Moreover, for Type-1, the E-field near the short-circuit surface is significantly greater than that near the output port side due to the asymmetrical structure of RF window. However, this phenomenon has been greatly improved in the proposed RF windows. The heat load because of RF power absorption over the ceramic has been calculated. The distribution of heat load in three new windows is more uniform and less than that in Type-1, and the heat load in Type-2 is about half of that in Type-1. The thermal and structural analyses of RF windows predict the lower temperature and less mechanical deformation for the three new RF windows. Multipactor analysis is carried out to determine the safety at the operating power level.

Elimination of catastrophic optical mirror damage in continuous-wave high-power laser diodes using multi-section waveguides.

One of the persistent obstacles for high-power laser diodes (LDs) has been the catastrophic optical mirror damage (COMD), which limits the operating power level and lifetime of commercial high-power LDs. The output facet of LD reaches a critical temperature resulting in COMD, which is an irreversible device failure. Here, we fabricate multi-section LDs by tailoring the waveguide structure along the cavity that separates the output facet from the heat-generating lasing region. In this method, the LD waveguide is divided into electrically isolated laser and window sections along the cavity. The laser section is pumped at a high current to achieve high output power, and the window is biased at a low current with negligible heat generation. This design restricts the thermal impact of the laser section on the facet, and the window section allows lossless transport of the laser to the output facet. The lasers were operated continuous-wave up to the maximum achievable power. While standard LDs show COMD failures, the multi-section waveguide LDs are COMD-free. Our technique and results provide a pathway for high-reliability LDs, which would find diverse applications in semiconductor lasers.

Thermal management in high‐power Erbium Ytterbium doped fiber amplifiers for optimum efficiency

AbstractCladding pumping is considered to be one of the best amplification approaches in view of the capital and operational expenditure for the development of high‐power optical amplifiers. Such schemes use multimode high‐power pump lasers as the pumping sources and they give high power output in the range of 3–5 W to use in fiber‐to‐the‐home as well as optical cable television networks. With the requirement for high output power in multichannel cost‐efficient telecommunication systems, amplifier devices face some limitations during its operation at maximum operating power level. The major limitations are the thermal effects, damage thresholds, and available pump power. Effective thermal management is a better option to improve the pump power conversion efficiency and power scaling in high‐power fiber amplifiers. Analytical and experimental investigation of two approaches for the thermal management of a commercial 3 W amplifier is discussed. The first approach considers a regular Al 6063 heat sink‐heat spreader combination with forced air cooling. The structure of the heat sink is optimized and the performance is analyzed with Aluminum and copper material for the heat spreader. The second approach discusses a thermoelectric cooler‐heat sink combination and the analysis results showed better thermal management during the high‐temperature operation of the amplifier. Two heat sink materials are considered in the analysis and results are discussed in the paper. Considering the cost‐effectiveness of the proposed solution, the thermoelectric cooler and Aluminum heat sink assembly are validated.

Maximizing Energy Extraction from Direct Grid Coupled PMSG For Wind Energy Conversion Systems

Direct grid coupling of permanent magnet synchronous generators (PMSG) for wind energy conversion systems (WECS) provides certain advantages with the penalties of maximum power point tracking (MPPT) and reactive power control. This paper proposes a novel PMSG design philosophy such that optimizing PMSG design at the initial stage would compensate for the drawbacks arising from the lack of an MPPT algorithm. Also, the ability to maintain a high power factor across a wide range of operating power levels is investigated by considering reactive power in the design process. In this study, optimization of slot/pole combination is described for direct grid coupled PMSGs to extract as much energy as possible according to wind data. A new benchmark, adequacy factor, is presented to determine the slot/pole combination. Variation of the reactive power is theoretically analyzed. A relationship is established between induced electromotive force (EMF), synchronous inductance values of machines, and the power factor. Fixed and variable speed operations of PMSGs are compared in terms of annual energy yield. Finally, theoretical analyses are validated through laboratory testing of prototype generators.

Investigation of Thermohydraulic Limits on Maximum Reactor Power in LEU Plate–Fueled, Pool-Type Research Reactor

In pool-type research reactors, the fuel core is placed in a large open pool of water, and it is consistently cooled by natural circulation. To meet the increasing demands of reactor-based research, i.e., neutron irradiation and isotope production, many institutes have been considering upgrading the designed power levels of their research reactors to maximize their utility. However, increasing operating power levels without replacing the major components of the reactor system is challenging because two important analyses must be extensively performed: (1) neutron transport analysis for nuclear fission and decay heat generation and (2) thermohydraulic analysis for heat removal in the core. In this paper, we investigate thermohydraulic limits on the maximum power of the Purdue University research reactor (PUR-1) using computational fluid dynamics (CFD) simulations which are coupled with the results from Monte Carlo neutron transport simulations. We design a PUR-1 fuel assembly, which is designated as the hottest one for CFD simulations, that includes a narrow, rectangular, and upward coolant channel. Here we demonstrate that the thermohydraulic limit for PUR-1 core power is 350 kW without changing the coolant system. Given a conservative safety margin, however, the estimated maximum power level is decreased to 170 kW. In the end, the results of two additional cooling systems—guide pipe and lowered coolant temperature—are presented to demonstrate the potential of advanced cooling capacity. They would enable reactors to operate at higher core power levels.

Adaptive second-order sliding-mode control for a pressurized water nuclear reactor in load following operation with Xenon oscillation suppression

This study proposes an adaptive second-order sliding mode control based on a twisting algorithm to control nuclear reactor core power during load-following power maneuvers. The control system was designed based on the concept of an extended equivalent control. The control technique does not require knowledge of the uncertainty or upper bound of the disturbance in the system. Additionally, the gain of the control system is a dynamic gain that increases or decreases according to the system requirements within a specified period. Consequently, chattering was attenuated. Chattering excites high-frequency dynamics and causes wear out of the control mechanism, making chattering a severe challenge in sliding-mode control. A nuclear reactor is a time-varying, complex, nonlinear, and constrained system. The characteristics of a nuclear reactor are a function of its operating power level, fuel burnup, and aging. In addition, the load-following mode of operation causes Xenon oscillation, which can further cause instability in the core. Therefore, the non-base load operation of the system, including load following, further aggravates uncertainty and disturbances in the system. To this end, an adaptive second-order sliding mode control that does not require knowledge of the uncertainty or the upper bound of the disturbance in the system was designed. The reactor core was modelled using an experimentally verified and validated multi-point kinetic model with four nodes. Simulation experiments were conducted using a multi-point kinetics model and an adaptive second-order sliding mode control. The results of the simulation experiments indicated that reactor core integrity is guaranteed, and the core is protected against peak power densities, such as linear heat generation rates (LHGRs) and lower departure from nucleate boiling ratios (DNBR). Moreover, the control system achieved the load-following objective and suppressed Xenon oscillation. The performance of the proposed control system was further compared with that of a twisting control system and classical proportional integral derivative control system to validate the effectiveness and reliability of the adaptive twisting second-order sliding mode control system.

Monitoring Operational States of a Nuclear Reactor Using Seismoacoustic Signatures and Machine Learning

Abstract Monitoring nuclear reactors is an important safety and security task with growing requirements. We explore the possibility of using seismic and acoustic data for inferring the power level of an operating reactor. Continuous data recorded at a single seismoacoustic station that is located about 50 m away from a research reactor was visualized and analyzed. The data show a clear correlation between seismoacoustic features and reactor main operational states. We designed a workflow that includes two machine learning (ML) models to classify the reactor operational states (OFF, transition, and ON) and estimate reactor power levels (10%, 30%, 50%, 70%, and 90%). We applied and compared five ML algorithms for the reactor OFF-transition-ON and four approaches for the power level classification. We also compared the performance of ML models trained with seismic-only, acoustic-only, and both types of data. Five-fold cross validations were implemented to assure a thorough evaluation of the model performances. The results show the extreme boosting gradient algorithm worked best for the first model, whereas random forests performed best for the second model. Combining seismic and acoustic data leads to better performance than using a single type of data. Seismic data contributed more than acoustic data for both models. We reached an accuracy of 0.98 for reactor OFF and ON. The accuracies for the transition state and power levels are less optimal with a minimum accuracy of 0.66. However, our results suggest seismic and acoustic data contain useful information about the transition state as well as power levels. Seismic and acoustic data could be integrated with other observations to improve monitoring performance.

Bifurcation Analysis of Xenon Oscillations in Large Pressurized Heavy Water Reactors with Spatial Control

Large nuclear reactors operating in the thermal spectrum are prone to both global and regional oscillations in power due to variation of 135Xe concentration. These power oscillations are self-stabilizing up to a certain operating power level, beyond which spatial power control becomes necessary for suppressing these oscillations. Especially for large pressurized heavy water reactors (PHWRs), which are natural uranium–fueled reactors using heavy water as coolant and moderator, the modes of xenon instabilities decide the extent and scheme for spatial power control. In this paper, the effect of spatial control on the bifurcation characteristics is demonstrated using a two-region model. The error signal for movement of the reactivity device has a global component for bulk power control and a local component for regional power control. The amount of regional power control determines the power level at which the spatial xenon oscillations stabilize. Using bifurcation analysis, it is found that in case of limited regional control, both supercritical and subcritical Hopf bifurcations exist, whereas in the case of increased regional control only supercritical Hopf bifurcations exist. However, these supercritical Hopf oscillations are due to time lag in control and have short timescales and lower amplitudes as compared to xenon oscillations. Hence, a proper choice of spatial control enables a PHWR to operate at rated full power capacity without any spatial Xenon instability.

A mixed integer optimization method with double penalties for the complete consumption of renewable energy in distributed energy systems

The flexible distributed energy system is an important strategic choice for all countries to develop the efficient consumption technology of abundant renewable energy. However, renewable energy with the obvious peak-valley, intermittence and randomness characteristics increases the difficulty of coordinately scheduling distributed units. This work proposes a mixed integer optimization model through designing a continuation method for integer decision variables and a constraint strategy with double penalties to ensure that the optimal start-stop states and optimal operating power level of distributed units are accurately configured under the premise of completely consuming renewable energy. A standard paradigm of modeling and operating optimization is further established for complex distributed energy systems to completely consume renewable energy, which is not limited to the system scale and the number of integer decision variables. The analysis results indicate that the proposed model simultaneously ensures the optimal start-stop states and operating power of distributed units. Compared with other methods, the proposed method reduces the switching times of start-stop states by 50% at least and improves the smoothness of operating power by 1.9%, moreover, it reduces the operating cost by 1.26% at least and saves the computing time by 79.2%. The proposed mixed integer optimization method has higher stability and robustness. It provides a reliable technology for the optimal operation of distributed energy systems, the flexible configuration of distributed units, and the complete consumption of high-proportion renewable energy.

Calculation of dose rates in loss of coolant accident due to double ended rupture of the experimental tangential irradiation beam tube of MTR reactor.

A MTR reactor is an open water pool reactor type. The water pool serves as a shield from radioactive radiations. The most serious accident in this type of reactor is the Loss of Coolant Accident (LOCA) due to rupture either of a primary coolant pipe or of any experimental beam tube. In the present work it has been assumed that pool water drains out due to double ended rupture of the tangential irradiation beam tube (TIC) which has a diameter 150 mm. For an operating power level of 22 MW, the equilibrium core would enter into melting conditions if the pool drain time is less than one hour. It was also assumed that Emergency Core Cooling System (chimney water injection system and siphon effect breaker were not working. The reactor interiors have been modeled using the Monte Carlo N-Particle Transport code MCNPX 2.7.0. The source term has been determined using the ORIGEN-2 code. The doses and dose rates calculations in different places of operator (as phantom of Tissue-Equivalent Material) inside of the reactor building were determined by using Monte Carlo N-Particle Transport (MCNPX).The results show that the dose rate in the control room would be 5.24557 SV/h, the dose rate in the reactor hall above the pools on the gate would be7.20137 SV/h and the dose rate in the Emergency control room would be 2.68239 SV/h. Those dose rates are extremely high and would lead to fatal doses in short time.

Calculation of dose rates in loss of coolant accident due to double ended rupture of the experimental tangential irradiation beam tube of MTR reactor

The doses and dose rates following a LOCA in MTR reactor have been studied. A MTR reactor is an open pool type. The water pool serves as a shield from radioactive radiations.The most serious accident in this type of reactor is the Loss of Coolant Accident (LOCA) due to rupture either of a primary coolant pipe or of any experimental beam tube. In the present work it has been assumed that pool water drains out due to double ended rupture of the tangential irradiation beam tube (TIC) which has a diameter 150 mm. For an operating power level of 22 MW, the equilibrium core will enter into melting conditions if the pool drain time is less than 1 h.It was also assumed that Emergency Core Cooling System (chimney water injection system and siphon effect breaker) were not working. Therefore, conservatively a severe damage (∼80%) is expected to occur to the core, either by a core uncover situation following extended boiling operation, or by a core covered situation with extended boiling.The reactor interiors have been modeled using the Monte Carlo N-Particle Transport code MCNPX 2.7.0. The source term has been determined using the ORIGEN-2 code. The doses and dose rates calculations in different places of operator (as phantom of Tissue-Equivalent Material) inside of the reactor building were determined by using Monte Carlo N-Particle Transport (MCNPX). The results show that the dose rate in the control room is 5.24 Sv/h, the dose rate in the reactor hall above the pools on the gate is 7.20Sv/h and the dose rate in the Emergency control room is 2.68Sv/h. Those dose rates are extremely high and would lead to fatal doses in short time.

Bifurcation Analysis of Spatial Xenon Oscillations in Large Pressurized Heavy Water Reactors Using Multipoint Reactor Kinetics with Thermal-Hydraulic Feedback

Conventionally, the stability of xenon oscillations is estimated by solution of the time-dependent neutron diffusion equation, coupled with iodine and xenon equations, by finding out the damping ratios in each case. This is performed for different initial perturbations and core burnup conditions and is a very time-consuming and tedious process. Some earlier studies include linear stability estimation, which is valid for small perturbations, but not much work has been done in nonlinear stability analysis for spatial xenon oscillations in particular. In this paper, an approach for carrying out bifurcation analysis of xenon oscillations in large pressurized heavy water reactors (PHWRs) is demonstrated using reduced-order models. The reduced-order model for studying spatial xenon oscillations consists of multipoint kinetic equations coupled with xenon and iodine equations along with explicit fuel and coolant temperature feedback. Both subcritical Hopf bifurcation and supercritical Hopf bifurcation in different parameter planes exist, which leads to unstable limit cycles in the linearly stable region (subcritical Hopf bifurcation) and stable limit cycles in the linearly unstable region (supercritical Hopf bifurcation). The stability map provides a total picture of the stability of the out-of-phase oscillations in a PHWR. Depending on the value of the fuel temperature coefficient of reactivity and coolant temperature coefficient of reactivity, one can determine the operating power level above which the out-of-phase xenon oscillations start to grow. This model can be used to analyze nonlinear stability characteristics without spatial power control, which is helpful in identification of stable/unstable regimes in different parameter spaces and is likely to aid in reactor design.

High-power operation and lateral divergence angle reduction of broad-area laser diodes at 976 nm

Broad-area diode lasers with high output power and low lateral divergence angle are highly desired for extensive scientific and industrial applications. Here, we report on the epitaxial design for higher output power and a flared waveguide design for reduced divergence, which leads to high power operation with a low lateral divergence angle. A vertically asymmetric epitaxial structure was employed and optimized for low internal optical loss and high efficiency to realize high output power operation. Using a flared waveguide design, the lateral divergence angle was efficiently reduced by decreasing the number of high-order lateral optical modes significantly. The flared waveguide design introduces a smooth modification of the ridge width along the cavity without deteriorating laser performance. Based on the optimized epitaxial and waveguide design, we scaled the waveguide width to realize high continuous-wave power of 34.5 W at 25 °C. A low lateral divergence angle of 8° and high power conversion efficiency of 60% were achieved at the operating power level of 25 W. The life test data (30 A at 45 °C for 39 units, 0 failures in 1000 h) demonstrated reliable operation illustrating the efficient design for reduced lateral divergence angle and high operating power.

Transient over-voltage analysis of the transmission system that renewable energy generation delivered through multi-HVDC

With the rapid development of renewable energy generation (REG) and HVDC projects, a large amount of renewable energy power is sent through single HVDC, or even multiple HVDCs. In this application scenario, the transient over-voltage at the sending-end of HVDC, caused by commutation failure or a blocking fault of HVDC, is the primary constraint on the HVDC operating power level. This paper analyses the transient over-voltage risk of the transmission system, that REG delivered through multiple HVDCs, and its mechanism is proposed. It is pointed out that multiple HVDCs having both same sending-end and receiving-end, or adjacent HVDCs having same sending-end and meanwhile the sending-end grid is weak, will increases the risk of transient over-voltage. Based on the short-circuit ratio and the multi-HVDC short-circuit ratio, a simplified practical calculation method of the transient over-voltage of the transmission system with REG delivered through multiple HVDCs is proposed. Finally, through simulation, the correctness of the above conclusions is verified.

Changes of the Neutron Flux of the Nuclear Reactor Triga Mark III Since the Conversion from High to Low 235U Enrichment

The neutron flux of the Triga Mark III research reactor was studied using nuclear track detectors. The facility of the National Institute for Nuclear Research (ININ), operates with a new core load of 85 LEU 30/20 (Low Enriched Uranium) fuel elements. The reactor provides a neutron flux around 2 × 1012 n cm-2s-1 at the irradiation channel. In this channel, CR-39 (allyl diglycol policarbonate) Landauer® detectors were exposed to neutrons; the detectors were covered with a 3 mm acrylic sheet for (n, p) reaction. Results show a linear response between the reactor power in the range 0.1 - 7 kW, and the average nuclear track density with data reproducibility and relatively low uncertainty (±5%). The method is a simple technique, fast and reliable procedure to monitor the research reactor operating power levels.

Generation of static and dynamic small calibration forces and their measurements by electromagnetic force compensation balance

The paper presents some of the results of the static and dynamic force measurements at 100 nN to sub-10 µN ranges which are generated due the photon-momentum. The force sensor with resolution about 20 nN and operating in differential measurement mode is developed by two electromagnetic force compensation balances. In order to generate these calibration forces, CW lasers with different operational modes, power levels, and wavelengths are used. Multi-reflection configuration of the laser beam inside the macroscopic cavity with highly reflective mirrors are used to test and variate the total amount of the forces.

Validation and improvement of gamma heating calculation methods for the G.A. Siwabessy multipurpose reactor

Gamma heating, which is deposited in irradiated targets or samples, is an important issue in research reactors because it affects the safety of samples and the reactor operation. Gamma heating in the Reaktor Serba Guna G.A. Siwabessy (RSG GAS) can be measured or calculated using computer code. In this paper, we present the results obtained by using gamma calorimeters to measure the gamma heating in the central irradiation position in RSG GAS. The measurement results were verified and then compared with the calculation results obtained using the Gamset code. However, the accuracy of the calculation results obtained using Gamset was inadequate, with more than 20% error. Moreover, Gamset was initially created to calculate gamma heating in 35 MWth reactors, and the RSG GAS reactor has an operating power level of 30 MWth. To address these issues, we developed a new program called NewGamset, built with an informative graphical user interface-based display. NewGamset can employ new analytical approaches as it utilizes a calculation base that comprises 18 energy groups and can provide updated physical parameters of RSG GAS. The results of gamma heating measurements obtained using gamma calorimeters made of graphite, aluminum, iron, and zirconium were 2.20 ± 0.03 W/g, 2.25 ± 0.02 W/g, 2.58 ± 0.03 W/g, and 2.91 ± 0.10 W/g, respectively. In general, the calculation results were larger than the measurement results, and the average ratio of calculation to measurement result was 1.37 for Gamset and 1.02 for NewGamset. Hence, it can be concluded that NewGamset provides more accurate results than Gamset. We also report the gamma heating estimation for common elements irradiated in the RSG GAS silicide core, with an operating power level of 15 MWth and 30 MWth. We highly recommend that NewGamset be used for validating the gamma heating data of various target materials in RSG GAS.